1. Field of the Invention
The present invention relates to an automatic flushing device that automatically flushes the urinal in response to a signal from a sensor, and more particularly to an automatic flushing device having a small dry battery as the power source for operation.
2. Description of Related Art
In general, an automatic flushing device A as shown in FIG. 1 connects through a check valve B with a water supply pipe C on its rear side, its bottom side connecting through a pipe D with a urinal E. The flushing device A includes a valve for allowing or interrupting water flow, a drive means for actuating the valve, a control circuit, and an infrared sensor. However, the conventional flushing devices employ a solenoid unit for actuating opening or closing of the valve, as shown in U.S. Pat. No. 4,742,583 dated May 10, 1988, resulting in large consumption of power.
Therefore, the conventional automatic flushing device employs a transformer to reduce the operating voltage from 110 V or 220 V to e.g. 6 V, 12 V or 24 V to supply low voltage current to the solenoid or employs a large dry battery to supply power to the solenoid. Further, its installation requires a separate wiring for power and additionally a leakage breaker for electrical safety, thus resulting in additional cost for installation by a qualified electrician.
Employing a small dry battery instead of the service power source or the large dry battery results in the problem that the used dry batteries must be replaced frequently with new ones.
Furthermore, the conventional automatic flushing device is in general constructed to have a valve for rapid opening or closing such that shocks (pressure surges) are likely to occur due to a large difference in water pressure during opening or closing operation producing a loud noise resulting from the impact of water. Such pressure surges, if repeatedly occurring, loosens or damage the Joints of the water pipe resulting in leakage of water; the damage being more serious in the case of old piping.
Also, whenever the valve opens, strong electric current flows through the solenoid coil and likely causes damage to the coil.
An object of the present invention is to eliminate the above drawbacks of the conventional automatic flushing device for a urinal and provide a novel automatic flushing device that employs a small dry battery for extended operation thereby eliminating the frequent replacement of the battery.
Another object of the invention is to provide an automatic flushing device for a urinal that can be easily installed in a building not having any power lines.
Still another object is to provide an automatic flushing device for the urinal that does not produce any impact phenomenon (pressure surges) by water when opening or closing the valve.
A further object is to provide an automatic flushing device having a drive mechanism reducing the wear of its computers to a minimum for ensuring a long service life.